This invention relates to a rotary type construction machine such as hydraulic power shovel, hydraulic crane or the like, and also to cab, equipment housing cover and counterweight for such a construction machine.
Generally, rotary type construction machines such as hydraulic power shovels and hydraulic cranes are constituted by a self-propelled base carrier and a rotary body which is mounted on the base carrier, and a working mechanism which is mounted on a front portion of the rotary body to carry out, for example, ground excavating operations or other ground working operations.
As a typical example of conventional rotary type construction machines, a hydraulic power shovel is roughly described below with reference to FIGS. 13 through 20.
In FIG. 13, indicated at 101 is a crawler type base carrier, and at 102 is an upper rotary body which is rotatably mounted on the base carrier 101.
A working mechanism 103 which can be lifted up and down to excavate earth or to carry out other ground working jobs is mounted centrally on a front portion of the upper rotary body 102.
The upper rotary body 102 is largely constituted by a rotary frame 104, a cab 105 which is built on the rotary frame 104 to serve as an operator""s room, an equipment housing cover 106 serving as a housing for an internal combustion engine (not shown) and other equipments which are mounted on the rotary frame 104, and a counterweight 107 which is provided at the rear end of the rotary frame 104.
In the case of a hydraulic power shovel of this sort, outer surfaces of the cab 105, equipment housing cover 106 and counterweight 107 of the upper rotary body 102 are usually coated with a weather-proof oil paint such as a polyurethane paint or the like.
In many cases, construction machines such as hydraulic power shovels are normally stored in a roofless storage place, exposed to rain or other weather conditions, particularly during a period between final assembling and shipment. While being stored in such a way in an outdoor storage place, the painted surfaces of the cab 105, equipment housing cover 106 and counterweight 107 of the upper rotary body 102 are beaten by rains and degraded considerably by development of a large number of streaky stains 108 (hereinafter referred to as raindrop stains 108) on vertical portions of the coated surfaces as shown in FIG. 14.
Reference is now had to FIGS. 15 and 16, which show on an enlarged scale the encircled portion A in FIG. 14, for the explanation of the conditions of the coating and raindrop stains 108 on the outer surface of the equipment housing cover 106.
As shown in these figures, an under coat 110 of an anti-corrosive alkyd or urethane resin paint is formed on the outer surface of a steel plate 109 which constitutes the equipment housing cover 106, and a top or finishing coat 111 is formed on the surface of the under coat 110. In this regard, the top coat 111 is normally formed by the use of a water repellent oil paint for protection against rains, for example, by a solid paint such as acrylic resin paint, polyurethane paint or the like. Namely, the top coat 111 is formed by applying a solid paint on the under coat 110.
The above-mentioned raindrop stains 108 are formed by fine particles of oily contaminant substances 112, such as carbon compounds in exhaust gases of an internal combustion engine and spattered particles of grease coming from bearings of the working mechanisms 103, which are trapped by raindrops and flow down with rain drops along the surface of the top coat 111 of a side plate 106A, leaving thereon streaky stains.
The raindrop stains 108 are formed through a number of stages as explained below in greater detail with reference to FIGS. 17 to 20.
Firstly, as shown in FIG. 17, fine particles of contaminant substances 112, such as carbon compounds in exhaust gases and spattered particles of grease, fall and deposit on the surface of the top coat 111 which is formed on the outer surface of a top plate 106B of the equipment housing cover 106.
Nextly, as shown in FIG. 18, raindrops 113 which have fallen on the top coat 111 of the top plate 106B temporarily dwell thereon substantially in the form of semispherical mound-like water drops as indicated at 114. Therefore, the deposited particles of contaminant substance under the water drops 114 tend to float up off the surface of the top coat 111. At this time, since the top coat 111 is of a water-repellent oil paint, the water drops 114 sit on the surface of the top coat 111 with a large contacting angle xcex81, for example, with a contacting angle xcex81 larger than 80 degrees.
Then, as shown in FIGS. 19 and 20, the raindrops 114 on the top coat 111 are connected with each other to form a water pool 115, which then starts dripping from the top plate 106B along the side plate 106A together with particles of the contaminant substances 112 which are entrained on dripping water drops 116. At this time, particles of the contaminant substances 112 which float on the surfaces of the dripping water drops 116, stick to the surface of the top coat 111 along the dripping courses of the water drops 116.
Consequently, particles of the contaminant substances 112 deposit and accumulate on the outer surface of the side plate 106A in streaks along the courses of dripping water drops 116, forming a large number of raindrop stains 108 thereon as a result of repetition of the above-described contaminant deposition mechanism.
As explained above, due to the lipophilic property of the top coat 111 which covers the outer surface of the equipment cover 106, the raindrop stains 108 are easily formed by aggregated deposition of the oily contaminant substances 112. The raindrop stains of this sort are difficult to wash off with water, and detrimental particularly to the construction machine rental business because degradations in outer appearance quality will lower the value of the merchandise to a considerable degree.
In view of the problems of the prior art as described above, it is an object of the present invention to provide a rotary type construction machine, and a cab, an equipment housing cover and a counterweight for the rotary type a construction machine, which have outer surfaces less susceptible to deposition of contaminants and which permit to wash off stains of deposited contaminants very easily, if any, to maintain the quality in outer appearance of a rotary body of the construction machine for a prolonged period of time.
In accordance with the present invention, the above-stated objective is achieved by the provision of a rotary type construction machine having a self-propelled base carrier and a rotary body rotatably mounted on said base carrier, which is characterized in that a hydrophilic film coating is provided on outer surfaces of the rotary body.
With the arrangements just described, raindrops or sprinkled wash water falling on the outer surfaces of the rotary body come into intimate contact with the hydrophilic film coating and form a water film on the surface of the hydrophilic film coating. As a consequence, stains of oily contaminants which have deposited on the outer surfaces of the rotary body are urged to float up on the water film and can be easily removed along with the water film as it flows down on and along the outer surfaces of the rotary body.
The above-mentioned hydrophilic film coating according to the present invention is preferred to be provided at least on vertically disposed outer surfaces of the rotary body. By this arrangement, oily contaminants which have deposited on outer surfaces of the rotary body are urged to flow down with the water film which is formed on vertical outer surfaces of the rotary body. It follows that the deposited contaminants can be easily removed along with raindrops or sprinkled wash water which form the water film.
The hydrophilic film coating can be formed by the use of a hydrophilic coating agent which is coated on outer surfaces of the rotary body and is capable of forming a water film to float up and wash away therewith stains or contaminants deposited on outer surfaces of the rotary body. By this arrangement, oily contaminants which have deposited on outer surfaces of the rotary body can also be easily removed since they are urged to float up on and flow down with a water film which is formed by raindrops or sprinkled wash water.
Further, the hydrophilic film coating according to the present invention is arranged to have a water contacting angle smaller than 60 degrees. By this arrangement, raindrops or sprinkled wash water falling on the surface of the hydrophilic film coating quickly comes into intimate contact with the hydrophilic film coating to form a water film thereon in an accelerated manner.
Further, according to the present invention, in a rotary type construction machine including a self-propelled base carrier, and a rotary body rotatably mounted on the base carrier and having a cab mounted thereon to serve as an operator""s room, preferably a hydrophilic film coating is provided on outer surfaces of the cab. By this arrangement, oily contaminant substances which have deposited on outer surfaces of the cab can be easily removed along with a water film which is formed on and flowing down along the outer surfaces of the cab.
Further, according to the present invention, in a rotary type construction machine including a self-propelled base carrier, and a rotary body rotatably mounted on the base carrier and having an equipment housing cover to house therein an internal combustion engine along with other equipments of the construction machine, preferably a hydrophilic film coating is provided on outer surfaces of the equipment housing cover. By this arrangement, oily contaminant substances which have deposited on outer surfaces of the equipment housing cover can be easily removed along with a water film which is formed on and flowing down along the outer surfaces of the equipment housing cover.
Furthermore, according to the present invention, in a rotary type construction machine having a self-propelled base carrier, and a rotary body rotatably mounted on the base carrier and having a counterweight thereon, preferably a hydrophilic film coating is provided on outer surfaces of the counterweight. By this arrangement, oily contaminant substances which have deposited on outer surfaces of the counterweight can be easily removed along with a water film which is formed on and flowing down along the outer surfaces of the counterweight.
Moreover, in one preferred form of the present invention, the hydrophilic film coating is formed by coating a paint which contains a hydrophilic agent. By this arrangement, the hydrophilic film coating can be formed on outer surfaces of the rotary body simply by coating thereon a paint which is added with a hydrophilic agent.
Further, in another preferred form of the present invention, the hydrophilic film coating is formed by coating, on an under coat of the rotary body, a top coat of a solid paint which contains a hydrophilic agent. By this arrangement, the hydrophilic film coating can be formed on the outer surfaces of the rotary body simply by coating thereon, as a top coat, a solid paint which contains a hydrophilic agent.
Further, in still another preferred form of the present invention, the hydrophilic film coating is formed by coating, on a first top coat of the rotary body, a second top coat of a clear paint which contains a hydrophilic agent. By this arrangement, similarly the hydrophilic film coating can be formed on the outer surfaces of the rotary body simply by coating, as a second top coat, a clear paint which contains a hydrophilic agent.
Moreover, according to the present invention, in a cab which is mounted on a rotary frame of a construction machine and formed in a cab cover structure having front and rear plates, right and left side plates and a top plate, a hydrophilic film coating is provided at least on outer surfaces of the front and rear plates and the right and left side plates of the cab cover structure. With this arrangement, even if oily contaminant substances have deposited on outer surfaces of the cab while in use, for example, such contaminant substances can be easily removed along with a water film which is formed on the outer surfaces of the cab by sprinkled wash water or the like.
Further, according to the present invention, in an equipment housing cover which is mounted on a rotary frame of a construction machine and formed in a housing structure including at least right and left side plates and a top plate located between upper ends of the side plates, a hydrophilic film coating is provided at least on outer surfaces of the right and left side plates. With this arrangement, even if oily contaminant substances have deposited on outer surfaces of the equipment housing cover while in use, for example, such contaminants can be easily removed along with a water film which is formed on the outer surfaces of the equipment housing cover upon sprinkling wash water or the like.
Furthermore, according to the present invention, in a counterweight which is provided on a rotary frame and in the form of a mass of a shape having at least front, rear, top and bottom sides, a hydrophilic film coating is provided on outer surfaces of the counterweight at least on outer surfaces on the rear side thereof. With this arrangement, even if oily contaminant substances have deposited on outer surfaces of the counterweight while in use, for example, such contaminants can be readily removed along with a water film which is formed on the outer surfaces of the counterweight upon sprinkling wash water or the like.